063  
FXUS65 KBYZ 140239  
AFDBYZ  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE BILLINGS MT  
839 PM MDT THU AUG 13 2026  
   
KEY MESSAGES  
 
- WIDESPREAD PRECIPITATION IS FORECAST TODAY THROUGH SATURDAY.  
LOCALLY HEAVY RAINFALL IS POSSIBLE DURING THIS PERIOD, WITH A  
SLIGHT RISK OF EXCEEDING FLOOD GUIDANCE FOR AREAS EAST OF A  
ROUNDUP TO BILLINGS TO SHERIDAN LINE.  
 
- TEMPERATURES WILL BE WELL BELOW NORMAL TODAY THROUGH SATURDAY,  
AND POSSIBLY SUNDAY.  
 
- RETURN TO AVERAGE TEMPERATURES NEXT WEEK.  
 
 
   
DISCUSSION  
 
NEXT 7 DAYS...  
 
AN UPPER LEVEL LOW PRESSURE SYSTEM / TROUGH AXIS REMAINS CENTERED  
OVER THE GREAT BASIN TODAY. THIS IS ALLOWING FOR OUR REGION TO GET  
REPEATED VORT MAXES AS THEY MIGRATE NORTHEASTWARDS. SEVERAL MORE  
WEAK WAVES OF ENERGY WILL MOVE UP FROM THE GREAT BASIN INTO  
MONTANA THROUGH THE DAY SATURDAY. THIS WILL RESULT IN ROUNDS OF  
SHOWERS AND THUNDERSTORMS OVER THE NEXT 2-3 DAYS WITH PERIODS OF  
RELATIVELY DRY CONDITIONS IN THE AREAS OF AVA BEHIND THESE  
SHORTWAVES.  
 
NOW THAT WE ARE FIRMLY UNDER THE SHIELD OF CLOUDS THERE WILL BE  
LITTLE SEVERE THREAT WITH ANY OF THESE STORMS DUE TO THE LACK OF  
CAPE AND INCREASED CIN. WHAT REMAINS A THREAT THOUGH THE THE  
POTENTIAL FOR LOCALLY HEAVY RAINFALL. WHILE NO STORM IS FORECAST  
TO HAVE OVERLY IMPRESSIVE RAINFALL RATES, REPEATED SHOWERS OVER  
THE SAME AREAS COULD CAUSE SOME LOCALIZED FLOODING. THAT BEING  
SAID, WE HAVE BEEN QUITE DRY OVER THE PAST MONTH WHICH MEANS THAT  
THE GROUND SHOULD BE ABLE TO HOLD MOST OF THIS MOISTURE JUST FINE  
WITH MINIMAL FLOODING CONCERNS ON A REGION-WIDE SCALE.  
 
DUE TO THE RELATIVE WEAK STEERING FLOW THE UPPER LEVEL LOW WILL BE  
ALLOWED TO NATURALLY RETROGRADE OVER THE NEXT SEVERAL DAYS BEFORE  
MERGING WITH A SECONDARY ADVANCING LOW PRESSURE SYSTEM. THIS WILL  
PUT OUR AREA BACK UNDER A RIDGE AS IT BUILDS BACK IN FROM THE  
GREAT PLAINS. THE GOOD NEWS WITH THIS FEATURE THOUGH IS THAT IT  
WILL NOT BE NEARLY AS HOT AS THE PREVIOUS RIDGING PATTERN. SURFACE  
WINDS WILL REMAIN PRIMARILY OUT OF THE PLAINS, LIMITING ANY  
DOWNSLOPE EFFECTS AND KEEPING THE NEER-SURFACE ENVIRONMENT  
DECENTLY MOIST. ADDITIONALLY, THE APEX OF THIS RIDGE WILL BE  
ROUGHLY ALONG THE MT/SK BORDER MEANING THAT WE COULD SEE  
SHORTWAVES RIDE ALONG THE RIDGE BRINGING CHANCES FOR BRIEF  
COOLDOWNS AND / OR PRECIPITATION. ONE SUCH TROUGH COULD IMPACT THE  
AREA THIS TIME NEXT WEEK. WMR  
   
AVIATION  
 
A BROAD AREA OF LIGHT TO MODERATE PRECIPITATION WITH EMBEDDED  
THUNDERSTORMS AND LOCALIZED POCKETS OF HEAVY RAIN WILL SLOWLY  
CROSS THE AREA THIS EVENING, EXITING TO THE NORTHEAST IN THE EARLY  
MORNING HOURS TONIGHT. LIGHT UPSLOPE WINDS AND SATURATED LOW  
LEVELS WILL RESULT IN LOW STRATUS AND FOG DEVELOPMENT ACROSS MUCH  
OF THE AREA OVERNIGHT THROUGH LATE FRIDAY MORNING, WITH STRATUS  
LINGERING FOR SOME AREAS INTO THE AFTERNOON. MVFR/IFR CONDITIONS  
CAN BE EXPECTED WITH PRECIPITATION AND STRATUS/FOG OVERNIGHT INTO  
FRIDAY MORNING. STP  
 
 
   
PRELIMINARY POINT TEMP/POPS  
 
FRI SAT SUN MON TUE WED THU  
-----------------------------------------------------------  
BIL 058/072 057/074 055/082 057/084 058/079 056/081 056/083  
96/T 64/W 41/U 12/T 63/T 42/W 31/B  
LVM 048/073 046/076 045/081 047/082 047/078 045/079 045/081  
89/T 94/T 51/U 23/T 75/T 54/T 32/T  
HDN 054/074 053/076 050/083 052/087 053/081 051/083 051/085  
95/W 64/W 21/U 11/B 53/T 42/W 31/B  
MLS 059/074 055/075 052/083 056/087 057/080 054/083 055/084  
87/T 22/W 13/W 11/B 53/T 32/W 32/W  
4BQ 061/076 057/076 054/082 057/086 058/081 056/082 056/085  
86/W 23/W 35/T 11/B 43/T 43/W 32/W  
BHK 055/076 051/075 047/081 052/086 053/080 049/081 051/084  
79/T 32/W 01/U 01/B 34/T 42/W 32/W  
SHR 053/073 051/073 049/079 049/083 051/078 049/080 049/082  
85/T 77/T 52/T 12/T 35/T 44/T 22/T  
 
 
   
BYZ WATCHES/WARNINGS/ADVISORIES  
 
MT...NONE.  
WY...NONE.  
 
 
 
 
WEATHER.GOV/BILLINGS  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab MT Page
The Nexlab WY Page
Main Text Page